Enhanced resource unit allocation schemes for ofdma transmission in wlan

ABSTRACT

Systems and methods of transmitting a PPDU to or from a single user station (STA) in an OFDMA transmission by using multiple RUs. An access point (AP) allocates multiple RUs to an STA for an OFDMA transmission and correspondingly specifies the STA ID repeatedly in the user specific field of a SIG-B field in a downlink PPDU, or in the user information fields of a trigger frame. Alternatively, multiple AIDs of the STA can be specified in the user specific field or the user information fields instead of repeating the same STA ID. An indication may be inserted in the SIG-A field to indicate that the enhanced RU allocation scheme is used for the OFDMA transmission.

CROSSREFERENCE TO RELATED APPLICATION

This application claims the benefit of and priority to and is acontinuation of copending US patent application, Ser. No. 16/255,623,Attorney Docket Number MEDT-0037-01U00US, entitled “ENHANCED RESOURCEUNIT ALLOCATION SCHEMES FOR OFDMA TRANSMISSION IN WLAN,” with filingdate Jan. 23, 2019, which claims priority to U.S. Provisional PatentApplication No. 62/624,860, entitled “ENHANCED RESOURCE UNIT ALLOCATIONSCHEMES FOR OFDMA TRANSMISSION IN WLAN,” filed on Feb. 1, 2018, both ofwhich are hereby incorporated by reference in their entirety as if fullyset forth below.

TECHNICAL FIELD

Embodiments of the present disclosure relate generally to the field ofnetwork communication, and more specifically, to the field ofcommunication protocols used in wireless communication.

BACKGROUND OF THE INVENTION

Wireless local area networks (WLANs) and mobile communication deviceshave become increasingly ubiquitous, such as smart phones, wearabledevices, various sensors, Internet-of-Things (IoTs), etc. Orthogonalfrequency-division multiple access (OFDMA) is a widely used digitalmodulation scheme that enables multi-user (MU) access by allocatingresource units (RUs) to individual user stations. Each RU is composed ofa prescribed number of frequency subcarriers or tones, e.g., 13 tones,26 tones, 52 tones, or 106 tones, and etc.

According to the IEEE.11ax Standards and Specifications for highefficiency (HE)-WLAN, each user station in an OFDMA transmission isallocated with a single RU. This can impose a great constraint in theWLAN network performance and efficiency. For example, in order to use a20 MHz channel for an OFDMA transmission to or from two user stations,each station can be allocated with a 106-tone RU to maximize the channelusage efficiency as allowed by the IEEE.11ax Standards. However, evenwith allocation of this largest RU, there are two 13-tone RUs in thecenter of the 20 MHz channel left unused, causing loss of more than 10%of the spectral efficiency. In some preamble puncture scenarios, tomitigate the interference to the punctured subbands, adjacent RUs may benulled. Due to the HE WLAN RU allocation constraint, a large portion ofthe frequency channel is wasted and cannot be used.

This constraint can also undesirably reduce the frequency diversityduring wideband transmissions. For example, given an 80 MHz channel, thechannel response of an individual user station (the “first userstation”) typically exhibits good response characteristics in thenon-contiguous ranges of [0:20] MHz and [60:80] MHz, but has poorcharacteristics in the center [20:60] MHz range. In the case of an OFDMAtransmission that also involves another user station, the first userstation can only be allocated with an RU in either the [0:20] MHz or the[60:80] MHz range because only one RU can be allocated. As a result, dueto the constraint, frequency diversity cannot be fully exploited in sucha

SUMMARY OF THE INVENTION

Accordingly, systems and methods disclosed herein provide effective andbackwards-compatible communication protocols to enable flexibleallocation of multiple frequency subchannels (or resource units (RUs))to a single user for OFDMA transmissions in a wireless local areanetwork (WLAN), thereby enhancing spectral usage efficiency andfrequency diversity of the network.

Embodiments of the present disclosure include using an access point (AP)to allocate multiple RUs to a non-AP STA (or herein “STA” for brevityunless specified otherwise) for the STA to transmit or receive in anOFDMA transmission. The multiple RU allocation is communicated to theSTA by identifying the STA in multiple user fields in a packet preamble,each corresponding to a respective RU. The RUs allocated the STA can becontiguous or non-contiguous. In some embodiments, the packet has amulti-user (MU) format in which a plurality of user fields areoriginally defined for RU allocation to multiple users, each usercorresponding to a respective RU and identified by its STA ID in a userfield. By reusing the user fields in the MU format to allocate multipleRUs to a single user station, the user STA receiving the packet canstill recognize various packet fields correctly and decipher the RUallocation information based on the multiple user fields. This reusedpacket portion advantageously causes no incorrect operation ortransmission interference by legacy receive STAs that do not support thereuse scheme, advantageously achieving backward compatibility with thelegacy receive STAs.

In some embodiments, for a downlink OFDMA transmission, the AP generatesa multi-user (MU) Physical Layer Convergence Protocol (PLCP) protocoldata unit (PPDU) which specifies the multiple RUs allocated to an STA inthe common field of the “SIG-B” field in the preamble. Correspondingly,the STA ID is repeated the same number of times in the multiple “STA-ID”fields of the “SIG-B” user field. Alternatively, multiple associationIDs (AIDs) of the same STA can be respectively specified in the multiple“STA-ID” fields. An additional indication can be inserted to the “SIG-A”field to indicate that multiple RUs are assigned to the STA. The PPDU isthen transmitted to the STA in OFDMA and by using the allocated multipleRUs. Upon receiving the PPDU, the STA resolves all the information thatis transmitted in the multiple RUs associated with its STA ID or AIDs.

For an uplink OFDMA transmission, the AP transmits a trigger frame toinitiate an STA to transmit a trigger-based PPDU in OFDMA to the AP. Inthe trigger frame, multiple RUs are specified in the user informationfield, and the same STA ID is repeated in the same number of times inthe “STA-ID” field of the user information fields. Alternatively,multiple association IDs (AIDs) of the same STA can be specified in the“STA-ID” fields. Upon receiving the trigger frame, the STA identifiesthe multiple RUs associated with its STA ID or AIDs and transmits a PPDUto the AP in OFDMA by using the multiple RUs.

According to embodiments of the present disclosure, the user fieldsdesigned for identifying multiple users are reused for identifying asingle STA and thereby associate the STA with the allocated multipleRUs. This advantageously enables multiple-RU allocation to a single STAwithout requiring a new packet format or any complicated modificationsin the current AP and STA products. Hence multiple-RU allocation to asingle STA can be achieved in a backward compatible manner.

The foregoing is a summary and thus contains, by necessity,simplifications, generalizations, and omissions of detail; consequently,those skilled in the art will appreciate that the summary isillustrative only and is not intended to be in any way limiting. Otheraspects, inventive features, and advantages of the present invention, asdefined solely by the claims, will become apparent in the non-limitingdetailed description set forth below.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will be better understood from areading of the following detailed description, taken in conjunction withthe accompanying figures, in which like reference characters designatelike elements.

FIG. 1A illustrates the format of an exemplary downlink (DL) HEmulti-user (MU) PPDU including indications of multiple-RU allocations toa single non-AP STA in accordance with an embodiment of the presentdisclosure.

FIG. 1B illustrates format of the “HE-SIG-B” field 140 in the exemplaryPPDU 100 in which an STA ID is repeated in the user specific fields incorrespondence to the multiple RUs allocated to one STA according to anembodiment of the present disclosure.

FIG. 1C illustrates the format of the “HE-SIG-B” field in the exemplaryPPDU in which different AIDs of an STA are assigned in the user fieldsin correspondence to the multiple RUs allocated to the STA according toanother embodiment of the present disclosure.

FIG. 2 illustrates the format of an exemplary uplink (UL) trigger frameused to trigger an OFDMA transmission from an STA by using multiple RUsin accordance with an embodiment of the present disclosure.

FIG. 3 is a flow chart depicting an exemplary process of allocatingmultiple RUs to an STA and transmitting a DL PPDU to the STA in OFDMA inaccordance with an embodiment of the present disclosure.

FIG. 4 is a flow chart depicting an exemplary process of transmitting atrigger frame from an AP to an STA in order to trigger a UL OFDMAtransmission from the STA by using multiple RUs in accordance with anembodiment of the present disclosure.

FIG. 5 illustrates the exemplary circuitry components and data flow inan exemplary transmitter configured for separate Low Density ParityCheck (LDPC) encoding and separate tone mapping and used to enableenhanced RU allocation in an OFDMA transmission in accordance with anembodiment of the present disclosure.

FIG. 6 illustrates the exemplary circuitry components and data flow inan exemplary transmitter configured for joint LDPC encoding and separatemodulation with respect to the steams associated with different RUsallocated to an STA in accordance with an embodiment of the presentdisclosure.

FIG. 7 illustrates the exemplary circuitry components and data flow inan exemplary transmitter configured for joint LDPC encoding and jointtone mapping with respect to the steams associated with different RUsallocated to an STA in accordance with an embodiment of the presentdisclosure.

FIG. 8 illustrates the exemplary circuitry components and data flow inan exemplary transmitter configured for joint LDPC encoding, jointstream parsing and joint tone mapping with respect to the steamsassociated with different RUs allocated to an STA in accordance with anembodiment of the present disclosure.

FIG. 9 illustrates the exemplary circuitry components and data flow inan exemplary transmitter configured for separate Binary ConvolutionalCodes (BCC) encoding and separate constellation mapping and used toenable enhanced RU allocation in an OFDMA transmission in accordancewith an embodiment of the present disclosure.

FIG. 10 illustrates the exemplary circuitry components and data flow inan exemplary transmitter configured for joint BCC encoding, joint BCCinterleaving and joint constellation mapping with respect to the steamsassociated with different RUs allocated to an STA in accordance with anembodiment of the present disclosure.

FIG. 11 is a block diagram illustrating an exemplary wirelesscommunication device capable of generating and transmitting an HE PPDUto an STA by using multiple RUs in an OFDMA in accordance with anembodiment of the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. While the invention will be described in conjunction with thepreferred embodiments, it will be understood that they are not intendedto limit the invention to these embodiments. On the contrary, theinvention is intended to cover alternatives, modifications, andequivalents which may be included within the spirit and scope of theinvention as defined by the appended claims. Furthermore, in thefollowing detailed description of embodiments of the present invention,numerous specific details are set forth in order to provide a thoroughunderstanding of the present invention. However, it will be recognizedby one of ordinary skill in the art that the present invention may bepracticed without these specific details. In other instances, well-knownmethods, procedures, components, and circuits have not been described indetail so as not to unnecessarily obscure aspects of the embodiments ofthe present invention. Although a method may be depicted as a sequenceof numbered steps for clarity, the numbering does not necessarilydictate the order of the steps. It should be understood that some of thesteps may be skipped, performed in parallel, or performed without therequirement of maintaining a strict order of sequence. The drawingsshowing embodiments of the invention are semi-diagrammatic and not toscale and, particularly, some of the dimensions are for the clarity ofpresentation and are shown exaggerated in the Figures. Similarly,although the views in the drawings for the ease of description generallyshow similar orientations, this depiction in the Figures is arbitraryfor the most part. Generally, the invention can be operated in anyorientation.

Enhanced Resource Unit Allocation Schemes for OFDMA Transmission in WLAN

Embodiments of the present disclosure are described in detail withreference to the Physical Layer Convergence Protocol (PLCP) protocoldata unit (PPDU) structure as defined in the high efficiency (HE) WLANbased IEEE 802.11 family of Specifications and Standards. However, thepresent disclosure is not limited to any specific packet formats orstructures, nor limited to any specific industry standards orspecifications.

Embodiments of the present disclosure provide communication protocolsfor transmitting a PPDU to, or from, a single user station (STA) in anorthogonal frequency division multiplexing access (OFDMA) transmissionby using multiple frequency subchannels, e.g., multiple resource units(RUs). Herein, the scheme of allocating multiple RUs to a single userSTA may be referred to as enhanced RU allocation scheme. In someembodiments, an access point (AP) allocates multiple RUs to an STA foran OFDMA transmission and correspondingly specifies the STA IDrepeatedly in the user specific field of a “SIG-B” field in a downlinkPPDU, or in the user information field of a trigger frame.Alternatively, multiple AIDs of the STA can be specified in the userspecific field or the user information field instead of repeating thesame STA ID.

FIG. 1A illustrates the format of an exemplary downlink (DL) HEmulti-user (MU) PPDU 100 including indications of multiple-RUallocations to a single non-AP STA in accordance with an embodiment ofthe present disclosure. The multiple RUs may be contiguous ornon-contiguous RUs and may have varying sizes. The PPDU 100 includes apreamble 110 and a payload 120. The PPDU 100 is generated by an AP andcarries data 150 encoded and modulated in multiple RUs and directed to asingle STA. The preamble 110 includes the short and long training fields(“L-STF,” “L-LTF,” “HE-STF,” and “HE-LTF”) and the signaling fields(“L-SIG,” “RL-SIG,” “HE-SIG-A,” “HE-SIG-B”).

The “HE-SIG-B” field 140 as defined in the current IEEE 802.11Specifications and Standards can provide DL MU RU allocation informationto allow multiple receive STAs to look up the corresponding RUs in thedata field of the packet. According to embodiments of the presentdisclosure, allocation of multiple RUs for a single STA is specified inthe “HE-SIG-B” field 140 as described in greater detail with referenceto FIGS. 1B and 1C.

An additional indication may be included in the “HE-SIG-A” field 130 toindicate the enhanced RU allocation scheme. For example, a reserved bit,e.g., B7, in “HE-SIG-A” is used. Based on this indication, the receiveSTA can determine whether to resolve only one user field or multiplefields in the “HE-SIG-B” as described in greater detail with referenceto FIGS. 1B and 1C.

FIG. 1B illustrates format of the “HE-SIG-B” field 140 in the exemplaryPPDU 100 in which an STA ID is repeated in the user specific fields incorrespondence to the multiple RUs allocated to one STA according to anembodiment of the present disclosure. For example, the “HE-SIG-B” field140 is separately encoded on each 20 MHz. The “HE-SIG-B” field 140includes a “Common Field” 160 and a “User Specific Field” 170. The“Common Field” 160 carries the RU allocation subfield for indicating theRU assignments in the frequency domain. Depending on the total bandwidthallocated to the PPDU, the “Common Field” 160 can contain multiple RUallocation subfields.

The “User Specific Field” 170 includes zero or more “User Block Fields,”e.g., field 171, 172 and 173 which may be followed by padding 174. Each“User Block Field” includes two user fields designed to containinformation for up to two STAs to decode their payloads, a cyclicredundancy check (CRC) sequence and a trail. Each user field includes a“STA-ID” field, the value of which represents the identification of theone or two STAs. Each user field may further include fields forinformation related to the STAs, such as number of spatial streams(e.g., “NSTS”), use of transmit beamforming (e.g., “TX Beam-forming”),modulation and coding scheme (e.g., “MCS”), dual carrier modulation(e.g., “DCM”) and coding mechanism (e.g., “Coding”).

For an MU PPDU that allocates different RUs to multiple user STAs, thevalues in the “STA-ID” fields of the user fields represent the STA IDs,e.g., two STA IDs in one user block field. According to embodiments ofthe present disclosure, the ID of one STA (STA ID) is repeated multipletimes in the one or more user fields in correspondence to the number ofRUs allocated to the STA. Once the STA receives the PPDU and locates theSTA IDs in the user fields, it can resolve all the information that istransmitted in the multiple allocated RUs. For any other STAs thatreceive the PPDU, including legacy STAs, this part of the information isignored and would not cause unwanted operations. That is, one STA can beallocated with multiple RUs for one OFDMA transmission in a backwardcompatible manner.

In some other embodiments, multiple STA IDs or associate station IDs(AIDs) are assigned to one STA, which can be specified in the one ormore user fields in correspondence to the number of RUs allocated to theSTA. FIG. 1C illustrates the format of the “HE-SIG-B” field 140 in theexemplary PPDU 100 in which different AIDs of an STA are assigned in theuser fields in correspondence to the multiple RUs allocated to the STAaccording to another embodiment of the present disclosure. Once the STAreceives the PPDU and locate the AIDs, the STA can resolve all theinformation that is the transmitted in the RUs and associated with itsSTA AIDs in the PPDU. Similarly, for any other STAs that receive thePPDU, including legacy STAs, this part of the information is ignored andwould not cause unwanted operations.

In some embodiments, the AIDs are assigned in the “HE-SIG-B” field 140in a particular order such that, when the STA locates one AID in thePPDU, it knows whether to wait to resolve for another RU allocation withits next AID.

It will be appreciated that, the downlink PPDU may be an MU PPDU anddirected to multiple user STAs and therefore also include RU allocationor spatial stream allocation information related to one or more otherSTAs besides the STA allocated with multiple RUs as described in FIGS.1A-1C. For example, the one or more other STAs may be allocated with asingle RU or multiple RUs.

To initiate an uplink OFDMA transmission in a WLAN, an AP may first senda trigger frame to an STA enclosing the RU allocation information.According to the RU allocation signaling in the trigger frame, the STAtransmits a PPDU to the AP in an OFDMA transmission and by usingallocated multiple RUs. The allocated RUs may be contiguous ornon-contiguous RUs and may have varying sizes. The trigger frame mayitself be included in a PPDU transmitted from the AP. FIG. 2 illustratesthe format of an exemplary uplink (UL) trigger frame 200 used to triggeran OFDMA transmission from an STA by using multiple RUs in accordancewith an embodiment of the present disclosure.

The trigger frame 200 includes a frame control field (e.g., “FrameControl”), a transmission duration field (“Duration”), receiver addressand transport address fields (“RA” and “TA”), a common information field(“Common Info”) and one or more user information field (“User info”), apadding (“Padding”) and a frequency check sequence (“FCS”). The commonfield 210 has a subfield used to indicate the type of trigger frame. Fora conventional MU transmission, each user information field 220 containsthe IDs of the multiple STAs to be triggered (e.g., “AID12”), allocatedRUs (“RU Allocation”), allocated spatial streams (“SS Allocation RandomAccess RU Information”) as well as other information required for theuplink MU transmission, such as coding type, modulation and codingscheme (“MCS”), dual carrier modulation (“DCM”), target received signalstrength indicator (“Target RSSI”), and trigger dependent userinformation.

According to embodiments of the present disclosure. The ID or IDs of asingle STA can be specified in the user information fields incorrespondence to the multiple RUs allocated to it. As shown, the “RUallocation” field 221 contains the information related to a number ofRUs allocated to a single STA, and the “AID12” field 222 repeats the STAIDs in the same number of times. In some other embodiments, the “AID12”field 222 lists different AIDs of the same STA in correspondence to themultiple-RU allocation specified in the “RU allocation” field 221. Therepeated STA ID or the list of AIDs in combination with the RUallocation information serve to signal the receive STA to generate asubsequent uplink PPDU (e.g., HE TB PPDU) and transmit the PPDU to theAP in OFDMA according to the allocated RUs.

It will be appreciated that, the trigger frame (e.g., in the form of anHE PPDU) may be directed to multiple user STAs and therefore also mayinclude RU allocation or spatial stream allocation information relatedto one or more other STAs besides the STA allocated with multiple RUsdescribed above. For example, the one or more other STAs may beallocated with a single RU or multiple RUs in another user informationfield 230.

FIG. 3 is a flow chart depicting an exemplary process 300 of allocatingmultiple RUs to an STA and transmitting a DL PPDU to the STA in OFDMA inaccordance with an embodiment of the present disclosure. At 301, an APallocates a plurality of RUs to an STA for transmitting an HE PPDU in adownlink OFDMA transmission. At 302, the AP generates the DL HE PPDU. At303, in the PPDU preamble, one or more user block fields in userspecific field of the HE-SIG-B field are set for the STA. Each userfield in a block field identifies the STA once by using the same STA IDor a different AID. In some embodiments, in correspondence to the numberof RUs allocated to the STA, an STA ID may be repeated the same numberof times in the user specific field, as shown in FIG. 1B. In some otherembodiments, different AIDs of the STA are assigned in the user specificfield, each corresponding to an RU allocated to the STA.

At 304, a particular bit in the HE-SIG-A field of the PPDU preamble isset to indicate that one STA is assigned with multiple RUs, or theenhanced RU allocation mode. At 305, encoding, constellation mapping andtone mapping are performed on the PPDU according to the RU allocation.At 306, the PPDU is transmitted to the STA in a DL OFDMA transmissionthrough a wireless network by using the allocated multiple RUs.

FIG. 4 is a flow chart depicting an exemplary process 400 oftransmitting a trigger frame from an AP to an STA in order to trigger aUL OFDMA transmission from the STA by using multiple RUs in accordancewith an embodiment of the present disclosure. At 401, the AP allocates aplurality of RUs to an STA for a UL OFDMA transmission. At 402, an HEPPDU is generated which includes a trigger frame operable to trigger theSTA to transmit a PPDU to the AP in an OFDMA transmission. At 403, thecommon field in the trigger frame is set to indicate the type of thetrigger fame. At 404, one or more user information fields in triggerframe are set, where each field includes one or two RUs of the multipleRUs allocated to the STA and an ID or a list of IDs of the STA. In someembodiments, in correspondence to the number of RUs allocated to theSTA, the STA ID may be repeated the same number of times in the userinformation fields, as shown in FIG. 2. In some other embodiments,different AIDs of the STA are set in the user information fields, eachAID corresponding to an RU allocated to the STA.

At 405, encoding, constellation mapping and tone mapping are performedon the trigger frame PPDU. At 306, the PPDU is transmitted to the STA inDL OFDMA through a wireless network by using the allocated multiple RUs.At 406, the trigger frame PPDU is transmitted from the AP to the STA. Inresponse, the STA transmits an uplink PPDU (e.g., HE TB PPDU) in OFDMAto the AP by using the allocated multiple RUs as specified in thetrigger frame.

Each of the transmitters illustrated in FIGS. 5-10 may be included in anAP and operable to transmit a DL PPDU in OFDMA to an STA in the enhancedRU allocation scheme. Alternatively, each of the transmittersillustrated in FIGS. 5-10 may be included in an STA operable to transmita UL PPDU in OFDMA to an AP in the enhanced RU allocation scheme and inresponse to a trigger frame which specifies the RU allocation.

In some embodiments, information associated with each RU is encodedseparately. FIG. 5 illustrates the exemplary circuitry components anddata flow in an exemplary transmitter 500 configured for separate LowDensity Parity Check (LDPC) encoding and separate tone mapping and usedto enable enhanced RU allocation in an OFDMA transmission in accordancewith an embodiment of the present disclosure. In this example, two RUsare allocated to an STA for the OFDMA transmission, RU #1 and RU #2. Thepaths 510 and 520 are configured to generate information to be carriedin RU #1 and RU #2, respectively. In this embodiment, information to becarried by the two RUs is encoded separately and independently.Constellation mapping and LDPC tone mapping are performed on each RUindependently. In some embodiments, different coding rates andconstellation schemes can be used for the different RUs.

For example, the path 510 is configured to process data associated withRU #1, and includes an LDPC encoder 511, a stream parser 512, aconstellation mapper 513 and a LDPC tone mapper 514. The scrambled bitsof the data associated with RU #1 are fed to the path 510. In parallel,the path 520 is configured to process data associated with RU #2, andincludes an LDPC encoder 521, a stream parser 522, a constellationmapper 523 (assuming a two-point constellation scheme) and a LDPC tonemapper 524. The scrambled bits of the data associated with RU #2 are fedto the path 510.

In some other embodiments, all the RUs allocated to one STA is encodedusing one encoder and in a single code rate. Constellation mapping andtone mapping can be performed with respect to each RU eitherindependently or jointly depending on the embodiment. FIG. 6 illustratesthe exemplary circuitry components and data flow in an exemplarytransmitter 600 configured for joint LDPC encoding and separatemodulation with respect to the steams associated with different RUsallocated to an STA in accordance with an embodiment of the presentdisclosure.

In this example, RU #1 and RU #2 are allocated to one STA for the OFDMAtransmission and the scrambled bits associated therewith are jointlyencoded in a single code rate and by using one encoder 610. Two streamparsers 612 and 622 are used to parse the streams associated with RU #1and RU #2 respectively. Similarly, two constellation mappers 613 and 623and two tone mappers 614 and 624 are used to operate on the streamsassociated with RU #1 and RU #2 respectively.

In some embodiments, a joint encoder can be associated with a singleLDPC tone mapper that maps the modulated tones across all the RUsallocated to the STA. FIG. 7 illustrates the exemplary circuitrycomponents and data flow in an exemplary transmitter 700 configured forjoint LDPC encoding and joint tone mapping with respect to the steamsassociated with different RUs allocated to an STA in accordance with anembodiment of the present disclosure. In this embodiment, a jointencoder 710 is used to encode the scrambled bits associated with bothRUs allocated to the STA. Two stream parsers 711 and 722 are used toparse the streams associated with RU #1 and RU #2 respectively. A singleLDPC tone mapper 714 is used to map the modulated tones (output from theconstellation mappers 713 and 723) associated with both RU #1 and RU #2by interleaving.

In some embodiments, a joint encoder can be associated with a singlestream parser and a single LDPC tone mapper that maps the modulatedtones across all the RUs allocated to the STA. FIG. 8 illustrates theexemplary circuitry components and data flow in an exemplary transmitter800 configured for joint LDPC encoding, joint stream parsing and jointtone mapping with respect to the steams associated with different RUsallocated to an STA in accordance with an embodiment of the presentdisclosure. In this embodiment, a single joint encoder 810 is used toencode the scrambled bits associated with both RUs allocated to the STA.A single stream parser 820 is used to parse the streams associated withRU #1 and RU #2. A single LDPC tone mapper 840 is used to map themodulated tones (output from the constellation mapper 830) associatedwith both RU #1 and RU #2 by interleaving. In this configuration, thestreams of both RUs have the same special streams and the sameconstellation mapping.

FIG. 9 illustrates the exemplary circuitry components and data flow inan exemplary transmitter 900 configured for separate BinaryConvolutional Codes (BCC) encoding and separate constellation mappingand used to enable enhanced RU allocation in an OFDMA transmission inaccordance with an embodiment of the present disclosure. In thisexample, two RUs are allocated to an STA for the OFDMA transmission, RU#1 and RU #2, and information associated with each RU is encoded in BCCseparately. The paths 910 and 920 are configured to generate informationcarried in RU #1 and RU #2, respectively. In this embodiment,information to be carried by the two RUs is encoded in BCC separatelyand independently. Streaming parsing, BCC interleaving and constellationmapping are also performed with respect to each RU independently. Insome embodiments, different coding rates and constellation schemes canbe used for the different RUs.

For example, the path 910 is configured to process the scrambled bitsassociated with RU #1, and includes a BCC encoder 911, a stream parser912, a BCC interleaver 913, a constellation mapper 914. In parallel, thepath 920 is configured to process the scrambled bits associated with RU#2, and includes a BCC encoder 921, a stream parser 922, a BCCinterleaver 923, a constellation mapper 924.

In some embodiments, a joint BCC encoder can be associated with a singlestream parser and a single BCC interleaver and a single constellationmapper. If all the RUs allocated to a single STA are encoded jointly,the BCC interleaver is configured based on the total coded bitscontained in all the allocated RUs.

FIG. 10 illustrates the exemplary circuitry components and data flow inan exemplary transmitter 800 configured for joint BCC encoding, jointBCC interleaving and joint constellation mapping with respect to thesteams associated with different RUs allocated to an STA in accordancewith an embodiment of the present disclosure. In this embodiment, asingle joint BCC encoder 1010 is used to encode the scrambled bitsassociated with both RUs allocated to the STA. A stream parser 1020 isused to parse the streams associated with RU #1 and RU #2. A BCCinterleaver 1030 interleaves the streams associated with RU #1 and RU #2jointly. A constellation mapper 1040 is used to map the interleavedtones associated with both RU #1 and RU #2 by interleaving.

FIG. 11 is a block diagram illustrating an exemplary wirelesscommunication device 1100 capable of generating and transmitting an HEPPDU to an STA by using multiple RUs in an OFDMA in accordance with anembodiment of the present disclosure. The communication device 1100 maybe an AP or an STA device having a transceiver configured for datacommunication, e.g., a general purpose computer, a smart phone, aportable electronic device, a tablet wearable device, a sensor used onInternet of Things (IoT), and etc.

The device 1100 includes a main processor 1130, a memory 1120 and atransceiver 1140 coupled to an array of antenna 1101-1104. The memory1120 stores the HE PPDU formats including the format of signaling theenhanced RU allocation to a single STA as described in detail withreference to FIGS. 1A-2. The memory also stores processor-executableinstructions that implement an enhanced RU allocation module 1122 and HEPPDU generation module 1123. The enhanced RU allocation module 1122 mayuse any suitable RU allocation algorithms, methods or policies toallocate multiple RUs to an STA without departing from the scope of thepresent disclosure. The HE PPDU generation module 1123 can generatesignaling and indications related to the enhanced RU allocation in theHE-SIG-B and HE-SIG-A fields as described with reference to FIGS. 1A-4,as well as other sections of the PPDU.

The transceiver 1140 includes a signal processor 1150 having variousmodules of the transmit path which is configured to generate eachsection of a PPDU or any other type of communication transmission unit.For instance, the signal processor 1150 includes a transmitFirst-In-First-Out (TX FIFO) 1111, an encoder 1112, a scrambler 1113, aninterleaver 1114, a constellation mapper 1115, an inversed discreteFourier transformer (IDFT) 1117, and a guard interval (GI) and windowinginsertion module 1116.

It will be appreciated that the transceiver 1140 in FIG. 11 may includea wide range of other suitable components that are well known in theart. The various components can be implemented in any suitable mannerthat is well known in the art and can be implemented using hardware,firmware and software logic or any combination thereof. Further, in someembodiments, the transceiver 1140 in FIG. 11 may as well include thecomponents in a receiving path.

Although certain preferred embodiments and methods have been disclosedherein, it will be apparent from the foregoing disclosure to thoseskilled in the art that variations and modifications of such embodimentsand methods may be made without departing from the spirit and scope ofthe invention. It is intended that the invention shall be limited onlyto the extent required by the appended claims and the rules andprinciples of applicable law.

What is claimed is:
 1. A method of wireless communication, the methodcomprising: allocating a first resource unit (RU) and a second RU for anOrthogonal frequency-division multiple access (OFDMA) transmission;setting a common field of preamble of a Physical Layer ConvergenceProtocol (PLCP) protocol data unit (PPDU) to indicate multiple RUallocation; encoding data associated with the first RU and dataassociated with the second RU using a Low Density Parity Check (LDPC)encoder; and transmitting the PPDU in the OFDMA transmission, whereinthe PPDU comprises the data associated with the first RU and the dataassociated with the second RU.
 2. The method of claim 1, furthercomprising performing LDPC tone mapping on the data associated with thefirst RU and the data associated with the second RU.
 3. The method ofclaim 1, further comprising performing LDPC tone mapping on the dataassociated with the first RU and the data associated with the second RUusing an LDPC tone mapper
 4. The method of claim 1, further comprisingperforming constellation mapping on the first RU and the second RUseparately and independently.
 5. The method of claim 4, wherein theperforming constellation mapping on the first RU and the second RU usesdifferent constellation schemes.
 6. The method of claim 1, furthercomprising: performing stream parsing for the first RU using a firststream parser; and performing stream parsing for the second RU using asecond stream parser.
 7. The method of claim 1, wherein the encodingdata associated with the first RU and data associated with the second RUusing a Low Density Parity Check (LDPC) encoder uses a same coding rate.8. The method of claim 1, wherein the OFDMA transmission is a downlinkdata transmission of the PPDU, and wherein the preamble furthercomprises multiple user fields contained in a SIG-B field indicatingmultiple RU allocation.
 9. A wireless communication device comprising: aprocessor that causes the wireless communication device to allocate afirst resource unit (RU) and a second RU to a receive station for anOrthogonal frequency-division multiple access (OFDMA) transmission; anda transceiver, configured to: setting a common field of preamble of aPhysical Layer Convergence Protocol (PLCP) protocol data unit (PPDU) toindicate multiple RU allocation to the receive station; encode dataassociated with the first RU and encode data associated with the secondRU using a Low Density Parity Check (LDPC) encoder; and transmit thePPDU in the OFDMA transmission, wherein the PPDU comprises the dataassociated with the first RU and the data associated with the second RU.10. The wireless communication device of claim 9, wherein thetransceiver is further configured to perform LDPC tone mapping on thedata associated with the first RU and the data associated with thesecond RU using an LDPC tone mapper.
 11. The wireless communicationdevice of claim 9, wherein the encode data associated with the first RUis performed separately and independently from the encode dataassociated with the second RU.
 12. The wireless communication device ofclaim 9, wherein the transceiver is further configured to performconstellation mapping on the first RU and the second RU separately andindependently.
 13. The wireless communication device of claim 12,wherein the encode data associated with the first RU and encode dataassociated with the second RU using a Low Density Parity Check (LDPC)encoder uses a same coding rate.
 14. The wireless communication deviceof claim 9, wherein the transceiver is further configured to: performstream parsing for the first RU and using a first stream parser; andperform stream parsing for the second RU and using a second streamparser.
 15. The wireless communication device of claim 9, wherein thetransceiver is configured as an access point (AP) station and thereceive station is a non-AP station, wherein the OFDMA transmission is adownlink data transmission of the PPDU, and wherein the preamble furthercomprises multiple user fields contained in a SIG-B field indicatingmultiple RU allocation to the receive station.
 16. A method of wirelesscommunication, the method comprising: allocating a first resource unit(RU) and a second RU for an Orthogonal frequency-division multipleaccess (OFDMA) transmission; setting a common field of preamble of aPhysical Layer Convergence Protocol (PLCP) protocol data unit (PPDU) toindicate multiple RU allocation to the receive station; performing LDPCtone mapping on data associated with the first RU and data associatedwith the second RU using an LDPC tone mapper; and transmit the PPDU inthe OFDMA transmission, wherein the PPDU comprises the data associatedwith the first RU and the data associated with the second RU.
 17. Themethod of claim 16, further comprising encoding data associated with thefirst RU and data associated with the second RU using a Low DensityParity Check (LDPC) encoder.
 18. The method of claim 16, furthercomprising parsing a stream associated with the first RU and a streamassociated with the second RU using a stream parser.
 19. The method ofclaim 16, further comprising performing constellation mapping on thefirst RU and the second RU using a same constellation mapping.
 20. Themethod of claim 16, wherein the OFDMA transmission is a downlink datatransmission of the PPDU, and wherein the preamble further comprisesmultiple user fields contained in a SIG-B field indicating multiple RUallocation.